Sewing-machine attachment



0. H. GENR-Y. SEWING MACHINE ATTACHMENT.

APPLICATION "FILED MAY 24x 1921.

Pand Mar. 7,1922k 0 lll H OOOOOO ooooo^ Y WITNESS/5S A TTORNEYS UNITEDSTATES PATENT OFFICE.

OLIVERn HOWARD GENTRY, or ROCHESTER, NEW YORK.

SEWING-MACHINE ATTACHMENT.

Application iled May 24,

To all whom t may concern Be it known that I, OLIVER I-I. GENTRY, acitizen of the United States, and a resident of Rochester, in the countyof Monroe and .State of New York, have invented a new and ImprovedSewing-Machine Attachment, of which the following as a full, clear, andexact description.

This invention` relates to sewing` machine attachments. Prior to thisinvention single spring attachments were used to assist the operator butif he did not use proper precaution on stopping they might cause themachine to run backward one or more revolutions which often broke thethread or needle.

The object of this invention is to produce a spring-balance device thatmay be attached to any sewing machine and so adjusted as to be ofassistance to the operator and which eliminates the danger of runningthe machine backwards when the operator ceases to apply the drivingforce.

This object is accomplished by providing, in conjunction with thetreadle of a sewing machine, a lever-carrying means having a lever atright angles thereto, and means for balancing the lever in a verticalposition.

This invention will be more clearly understood from the followinodetailed description and accompanying crawings.

Figure 1 is a top plan View of the device showing it attached to asewing machine; and

Figure 2 is a side elevation showing it connected to a sewing machine.

Referring to the above-mentioned figures, a treadle 1 is mounted on theshaft 2 which is carried by the frame 3 of the sewing machine. A metal.strip fl, which has a hook member 5 at one end and a supporting stud Cat the other, has connected to the end which carries the stud a threadedbolt meniber 7. Clip S which has an opening therethrough fits over thebolt member 7 and is held thereon by means of a wing nut 9 which engageswith the bolt 7. This metal strip may be connected to the treadle of anysewing machine by fitting the hook member 5 over one side of the treadle1, and clip 8 over the other, and adjusting the wing nut 9 to clamp itin position. The stud 6 engages with the top of the treadle l so as toSpecification of Letters Patent.

. by means of Patented Mar. *7, 1922.

1921. Serial No. 472,041.

eliminate any vibration of the metal strip that might take place duringt-he operation of the treadle.

A metal plate 18 is fixed to the metal strip a and extends at rightangles thereto. Fixed to the metal plate 13 are headed pins 111 whichare arranged in vertical rows. Clamps 10 are fitted on the frame 3 andheld in engagement therewith by means of hook-headed bolts 11 and wingnuts 15, which engage with these bolts. The plate 13, which really formsa lever arm, is connected to the clamps 10 mounted on the frame 3springs 12 which are extended between the hook-headed bolts 11 and theheaded pins let fixed to the plate 13.

lhen the treadle l is rocked on the shaft 2, the lever arm 13 oscillatesabout the shaft, and the oscillation of the lever arm in one directionextends one of the springs 12 and allows the other to contract. Onreaching a limit of oscillation the extended spring tends to draw thelever arm back to its ver tical position and thus assists the operator.If the operator at this point removes his foot from` the treadle theextended spring will move the lever arm towards its vertical position,and as it moves it will gain suflicient :momentum to carry it beyond avertical position, but any movement beyond a vertical position isretarded by the other spring which will then become extended, and soafter the operator ceases to apply force to the treadle the machine willbe brought to rest by the springs without making a revolution eitherbackward or forward.

Having thus described my invention, I claim as new and desire to secureby Letters Patent l. In combination with a sewing machine including aframe and treadle, a spring balance device comprising a strip mounted onthe treadle, a metal plate iixed to the strip and extending at rightangles thereto, and spring means for connecting the plate to cach sideof the frame.

2. In combination with a sewing machine including a frame and treadle, aspring balance device comprising a strip, adjustable means co-operatingwith the strip to conneet it to the treadle, a lever arm fixed to themetal strip and extending at right angles to it, and spring meansconnecting the lever anni to each side of the frame to balance it in a.vertical position.

3. In combination with 2L sewing machine including u. frame ancltreadle,@spring balance device comprising a. rigidustijip, arcljustable meanscooperating with the strip to' connect it to the treadle, a leverAextencling at right angles to jche strip and fixed to GLIVER HOWARDGENTRY

